Flotation of phosphate and similar ores



atented Aug. 14, 195i FLOTATION OF PHgSPH! YE AND SIMILAR RES Ira M. LeBaron, Lakeland, Fla., and Paul D. V.

Manning, Glencoe, Ill., assignors to International Minerals & ChemicalCorporation, a corporation of New York N Drawing. Application September11, 1947, Serial No. 773,504

9 Claims.

This application is a continuation-in-part of application Ser. No.722,296 filed Jan. 15, 1947, now abandoned.

The present invention relates to the process of beneficiating orconcentrating ores. More particularly, the process of the presentinvention relates to the beneficiating or concentrating of phosphaticores, or phosphorous-containing materials." In general, the process ofthe present invention is applicable to beneficiation of any nonmetallicore such as, for example, apatite, fluorapatite, sylvite, langebeinite,fluorspar, feldspar, and the like.

Appatite and fluorapatite, which are the crude phosphatic materials orminerals, occur widely in nature and are generally thought to be chieflytricalcium phosphate coupled with other minerals such as quartz,silicates, calcium carbonate, and the like, all of which, of, course,contain no phosphorus and are of little, if any, nutritive value sofaras plants and animals are directly concerned. Such materials, inaddition, contain traces of minor quantities of heavy metals, heavymetal'salt oxides such as ferric oxide, aluminum; and the like. Manymethods have been devised in the past for treating such ores to effectbeneficiation or concentration of the phosphatic constituents ofapatite, fluorapatite, and the like, while removing therefrom thesiliceous, carbonaceous and heavy metal constituents therefrom. Severalmethods involve the desliming, dewatering and separation of eitherpulpedor unpulped material in order to effect this beneficiation andconcentration. One commonly used method involves the reagentizing ofsuch dewatered ore with a collecting agent used in conjunction with arelatively high boiling hydrocarbon oil or liquid, together with the useof a basic component such as caustic. When an aqueous suspension orpulped phosphatic rock is reagentized with a composition containing thiscombination and the same agitated and aerated in an aqueous suspension,the phosphatic values and components of the rock are found to rise andbecome segregated in the upper portion of such suspension while thesiliceous values are found to settle or deposit in the lower portion ofsuch a suspension. The beneficiated or enriched phosphatic material iswithdrawn and further treated by reflotation for further beneficiatingof the phosphatic ore, and the material so segregated is eithersubjected to acid treatment for the production of superphosphate, or isground and sold as raw, enriched phosphate rock having from 60% to 75%,and even as high as 80%, of

2 tricalcium phosphate computed as bone phosphate of lime.

In such a process, however, it has been recognized that the collectingagents heretofore and presently employed in the reagentizing step areexpensive and in many instances require greater quantities of materialthan is economically feasible. Because of the bulky character of thebusiness of producing phosphate rock concentrates, and the highlycompetitive market existing in such a business, great effort has beenexpended to discover collecting agents which will be more eflicacious,yet which may cost even less than those heretofore employed. It is notalone de-' sirable to employ a collector which may. be used in smallerquantities to effect an efiicient segregation of the phosphatic values,but it is also necessary that the values recovered be of a relativelyhigh purity and relatively free of solids other than the desiredphosphatic material. To this end, the following invention is directed.

It is an object of the present invention to provide an improved processof concentrating or beneficiating ores.

It is a further object of this invention to provide an improved processfor concentrating or beneficiating phosphatic ores.

It is a further object of the present invention to provide an improvedprocess of concentrating or beneficiating phosphatic ores by the frothflotation method in which the reagent added for this purpose hasfrothing as well as collecting characteristics.

It is a further object of this invention to provide an improved processfor the beneficiating or concentrating of phosphatic ores in which thereagent added for the froth flotation or collecting step has improvedcharacteristics as to the froth breaking after the flotation step habeen completed.

It is a still further object of this invention to provide an .mprovedprocess for the beneficiating or concentrating of phosphatic ores orphosphorus-bearing materials wherein such material is reagentized. Inaddition, it is an object of this invention to provide an improvedreagentlzing composition which will give an improved recovery of thephosphatic values of the ore or rock, while at the same time requiring alesser quantity of the reagent than has heretofore been customarily usedof the reagent to accomplish the same or better recovery of the B. P. L.content of the ore or rock.

Still further objects of the invention will be apparent upon a morecomplete understanding has been practiced for many years. The presentinvention is directed to the discovery of and use of an improvedreagentizing composition for this purpou. Once the phosphatic material,such as Florida pebble phosphate rock or any other phosphatic rock suchas Montana or Tennessee rock,

has been sized to about 1 mm. more or less.

and if desired, washed with water to remove slimes and dewatered in aclassifier to separate water from the rock. the material is reagentizedwith the novel composition herein outlined. It has been discovered thatthe humin'produced in the acid hydrolysis of at least one crude protein,or mixtures thereof. and which is removed as a precipitate from thecrude hydrolysate contains certain beneficial values which are thesubject matter of this invention. It is not known exactly what thespecific chemical constitution of these values are. However, it has beendiscovered that the humin does accomplish the desired results for thebeneficiation of phosphatic materials when used in conjunction withother substances conventionally employed in such reagentizingoperations.

The term "crude protein" is used herein and in the appended claims todistinguish from protein which has been purified by various physicaland/or chemical means which are familiar to persons skilled in theprotein and amino acid arts. Such purified proteins produce mixtures ofamino acids upon hydrolysis which are essen -tially free fromcontaminating substances. In

Animal protcim-Meat fibre, meat residues, fish meal, bone meal, milkprotein, casein, blood, andothers. I

Vegetable protein.-Wheat gluten, corn gluten, soyabean gluten, fiaxseed,cottonseed, peanut cake, zein, cereals and grains, and others.

Such protein material is, at present, either discarded by the respectiveindustries, or is processe to produce animal or plant foods.

. The humin required as a reagentizing composition in the instantprocess may be produced either by acid hydrolysis of any one of theabove mentioned crude protein materials or by I acid hydrolysis ofvarious combined mixtures thereof. The humin may be used directly as itcomes from the filters in the acid hydrolysis of crude protein. However,because of the bulkiness of this product, it is economical andexpedient, so far as results are concerned, to prepare either an aqueousor organic extract of the humin, or the concentrate or residue of suchextracts. These extracts may be used as such, or the solvent may bedriven on leaving a residue which is substantially solvent free extractor residue, said residue then being used in the reagentizingcomposition. Distillates oi humin, prepared according to procedureshereinafter described, may also be employed. Of course, the moreconcentrated the desired values of the humin cake are, the less theamount required to accomplish the desired results in the separation ofthe phosphatic values from the reagentized phosphatic material.

Any of the conventional organic solvents appear to be satisfactory inpreparing the extract or concentrate therefrom for use in thereagentizing of phosphatic material. Thus, for example, all aliphaticethers such as diethyl ether, diisopropyl ether, the lower aliphaticalcohols such as methylalcohol, ethyl alcohol, normal propyl alcohol,isopropyl alcohol, and the various butyl alcohols, the petroleumsolvents such as petroleum ether, paper and varnish makers naphtha,kerosene, Diesel oil, fuel oil, and the like, may be used. In addition,such solvents as carbon tetrachloride, the chlorbenzenes, B,B-dichlor-diethyl ether, and the like, may also be employed. In fact,any of the common, conventionally used organic solvents seem to producean extract from the humin cake containing the desired values. Water maybe used as the solvent but the resultant extract is not as satisfactoryfor the purpose of the present invention as is the extract using theorganic solvents above stated.

In addition to the essential values of the humin cake, the reagentizedcomposition also contains a basic material such as caustic soda, sodaash, KOH, or the like, in order to regulate the pH of the suspension orpulped slurry used up to 7.0, preferably between about 8.0 and about9.0. Still a third component of the reagentized composition is a liquidhydrocarbon component which isa liquid under the conditions obtaining.Suitable substances in this category are Diesel oil,

fuel oil, kerosene, the heavier solvent naphthas, crude oil, and thelike. I

Each of the three above specified components of the reagentizedcomposition may be added separately or they may be added as a previouslyprepared admixture to the dewatered phosphatic material. Also, it ispossible to obtain substantial results in beneficiating the phosphaticrock or ore if the hydrocarbon component of the reagentizing compositionis omitted entirely. A typical composition may be prepared in thefollowing manner, the amounts being in pounds per ton of dewatered oretreated:

A. (1) Wet humin cake of 50% to 60% water content or the cake may be oisubstantially anhydrous character in an amount between about 0.5 andabout 3.0, preferably between about 1.5 and about 2.5, all on a drybasis. (2) Alcoholic extract of humin cake in an amount between about0.2 and about 3.0, preferably between about 0.75 and about 2.0.

B. Diesel or fuel oil in conventional amounts,-

usually between about 0.1 and about 6.0.

C. Caustic soda or any other suitable basic material in conventionalamounts, usually between about 0.2 and about 1.5.

A phosphatic rock reagentized with a composition as above described maybe subjected to a separation or segregation step, or sequence of suchsteps, in a number of ways, all of which efi'ect a marked beneficiationor concentration of the desired phosphatic values of the ore. Such areagentized feed may be slurried in water to form an aqueous suspension,allowing the froth layer and agglomerate layer to collect at the top ofthe flotation cell with the siliceous and other impurities and lessdesired values sinking to the bottom of such cell, in which case theterialmay then be subjected to still a further flotation or series offlotation steps employing the same reagentizing composition or adiiierent one to further beneficiate phosphatic values. One of theadvantages in the use of the instant reagentizing composition is that itis easily broken up and defrothed after flotation has been com- Dleted.This is accomplished by treating the floated phosphatic values withsulfuric acid to remove the oil and other reagents adhering to thephosphatic values. Lesser quantities of sul-.

tions of treatment and involved the same amounts of ore or rock. andthe'like, and except as indi cated in the table, all conditions,reagents, and

treatments remained constant so that a set of strictly comparableresults were obtained .with the exceptions noted in the table.

In each instance 1000 grams of Florida pebble rock of-about .28 mesh wasdeslimed and dewatered to about 70-80% solids, placed in 'a mixingchamber with reagent, and agitated for about one minute. The treatedmixture was then di-, luted with water, placed in a, flotation cell andagitated for about two minutes with the various furic acid, or any othermineral acid such as low:

Tuna I Humin obtained by acid hydrolysis of wheat gluten Example No I IIIII IV Solvent 2lbs. Petra. 'r Used (o llecm) Hum! ii ttft'. ill te c (1Toll on I I11 8 ype cake or Humin lbs. Hu m Cake Cake 'Rea ent, lbs. rton:

flollectoiz 3- 0 0. 3 5. 0 0.5. Petroleum Oil 3-0 3. 0 3.0 3.0. CausticSoda 0.6 0. 5 0.6.

P 53. r. L.inFeed, Weight Per CcnL. 29.6 29.6 29.6 29.6.

Recovered, Weight Per Cent. 34. 0 36. 7 34. 4 About that 0! II. B. P.L., Weight Per Cent 72.16 71.46 70.23 Do. B. P. L., ol Tails, Weight PerCent 6. 73 4. 92 7. 71 D0. f B. P. L., Recovery, Weight Per Cent 84. 089. 4 83. 7 D0.

hydrochloric acid, are required in breaking the Example, IV is presentedto show a comparison coatings on the phosphatic values than is the casewhenusing the reagentizing compositions heretofore employed.

The Iurther concentration and beneficiation of the phosphatic valuessegregated in the froth layer of the flotation cell may be treated asabove stated in the conventional manner to eiIect the desired degree ofconcentration of the B. P. L..

(bone phosphate of lime) content of the material.

The novel reagentizing composition may also be appleid in processesdesigned to beneficiate or concentrate phosphatic ores and othernon-metallicores previously mentioned in which flotation steps are notinvolved. Thus, for example, the reagentized phosphatic feed either hasan original or intermedaite step in the beneficiation, may be subject toa tabling operation of conventional construction to allow a collectionand segregation of phosphatic material on the one hand, and siliceousand heavy mineral bodies on-the other hand. Also, it has been discoveredthat phosphatic material reagentized with the novel composition hereindiscussed may be successfully beneficiated as to its phosphatic contentby conducting such reagentized feed in a downwardly spiraling path so asto permit the phosphatic material to be selectively centrifugally movedto the outer side of the spiral pathway, while the siliceous bodies andother impurities are collected from the inner portion of the spiralpathway.

As illustrative of the character of the instant invention, but in nowise intending to be limited thereby, the following examples aredescribed:

EXAMPLES In the following examples, each run was carried out under thesame set of standard condiof the efiectiveness of humin cake alcoholicextract for reagentizing phosphatic ore with crude tall oil, aconventionally used reagent for the same purpose. It is noted thatsubstantially thes'ame" degree of beneflciation is attained with the,al-

coholic extract in only 0.3 lb. per ton as is crude tall oil used in anamount of 0.5 lb. per

TABLE II Reagent-Solvent free extracts of humin cake from corn glutenhydrolysates.

Example No V VI VII VIII Alcohol Alcohol Benzene Crude Type Used(Collector) Extract Extract Extract 'l'all Oil Reageut lbs. per ton:

' Collector o. 35 0. 344 0. 505 o. 5 Petroleum oil 3.0 3.0 3.0 3.0Caustic soda 0. 5 0. 5 0. 5 0. 5 B. P. L. in Feed,

Weight Per Cent.-. 31. 9 32. 0 32. 2 29. 6 Product:

Recovered, Weight I?!) Per Cent 39. 0 38. 2 33. 2 34. 0 B. P. L., WeightPer Cent 68. 2! 70. 63 72. 8 72. 16 B. P. L., of Tails,

Weight Per Cent. 4. 21 4.81 8. 91 6. 73 B. P. L., Recovery,

Weight Per Cent.-- 92. 5 91.3 82.3 84. 0 d5 Example VIII is identicalwith Example IV. and is reproduced for purposes of The advantages ofemploying the alcoholic ex tracts are immediately apparent and thebenzene extract produces approximately the same degree of beneficiationas does the tall oil reagent compositions.

The humin distillate" mentioned previously herein and in the appendedclaims is a liquid or semi-liquid composition which is obtained bysubtypes of reagents in the amounts speciiled, be-

Cent Product, 13

mung the humin. obtained according to previinert atmosphere, and ateither atmospheric orreduced preaures. The amount of distillate'obassess? taimd in any particular distillation will-"depends I Isolv'ent-freeextracts thereof.

upon the temperature of the still. the pressure of the system, theefllciency oi condensing unit which cools the distillate, and upon thepal-tic tillates as ore beneflciationreagents.

In the following examples, each runwas ear-' 7? ried out employing theprocedures of-iExamples ItoVIII. Tut: III

Humin distillate obtained by suba'ecting humin,

obtained by acid hydrolysis of wheat (listen, to

a distillation totemperature up to 700917., in mono s I Example N0 IX QX XI Humin Humin Crude Distillate Distillate Type um (Collector) Tall onReagent, lbs. per ton:

ollector Petroleum oil Caustic soda B. 1?. L. in Feed, Weight Per L.,Recovery,

P. Weight Per Cent.

ExampleXI is identical to Example VIII and is reproduced for purposes ofcomparison.

Having now thus fully described and illustrated the invention, what isdesired to be secured and claimed by Letters Patent is: I Y I l. Theprocess of concentrating phosphatic ores which comprises agitating andaerating an aqueous suspension of said ore in admixture with at leastone substance selected from the group 'uiar humin being distilled. Ondistilling some i phatic ores, which comprises agitating and aeratingand aqueous pulp of said ore which has been reagentised with a collectorselected from the group consis of humin obtained as a precipi tate inthe hydrolysis of crude vegetable 1 protein; of said humin, organicsolvent of saidumin and solvent-free extracts thereo andaqueous extractsofsaid humin and '4. The process of wetbeneflclationofphosphs't'icorealwllich @Prisesagitating and tent-- w i an= aqueouspulp of said ore which has been reagentised with a collector sele'ctedfrom the.

group consisting ofhumin obtained as, a precipitate. in the acidhydrolysis of crude animal protein. distillates of said humin.organicsolvent extracts of said humin and solvent-free extracts Ithereof, and aqueous extracts of said humin ,is reagentized with adistillate of humimsaid solvent-free extracts thereof.

, '5. A process as in claim 2 wherein thesaid ore humin being obtainedas a precipitate in the acid hydrolysis of at least one crudeprotein.

1 6. A'process as in claim 3 wherein the humin employed is obtained as aprecipitate in the acid hydrolysis of corn gluten.

I. A'process as in-claim 3 wherein the humin I employed is obtained as aprecipitate in the acid t phatic ore in admixture with at least onesub-' hydrolysis of wheatgluten.

I 8. The process which comprisesagitating and aerating anaqueous pulpsuspension of phosstance selected from the group con'sistingof huminobtained as a precipitate in theacidhydrolr' sis of crudeproteinydistillates of said humin, organic solvent extracts of saidhumin and solvent free extracts thereof, and aqueous extracts of saidhumin and solvent-free extracts thereof, and in admixture'with causticand a hydrocarbon oil andseparating the upper layer from the suspension.

9. The process of concentrating pulpcd nonmetallic ores which comprisesreagentizing said pulpcd are with at least one substance selected fromthe group consisting of humin obtained as a precipitate in the acidhydrolysis of crude protein, distiliates of saidhumin, organic solventextracts of said humin and solvent-free extracts thereof, and aqueousextractssof said humin and consisting ofhumin obtained as a precipitatein tate in the acid hydrolysis of crude protein. distillates of saidhumin, organic solvent'extracts of said humin and solvent-free extractsthereof, and aqueous extracts of said humin and solventfree extractsthereof. j

3. The process of wet beneflciation of phossolvent-free extractsthereof. agitating and aerating the same in aqueous medium andseparating the upper layer from the-aqueous suspension. IRA M LE BARON.

PAUL D. V. MANNING.

REFERENCES crran i The following-references areof record in the file ofthis patents UNITED STATES ra'r lm'rsf Number Name Date 2,269,958Urquhart Jan. 13, 1942 2,299,893 Greene Oct. 27, 1842 2,361,057 Ratzer'Oct. 27. 1942 FOREIGN PATENTS Number Country Date 789,280 France Alli.12, 1935

1. THE PROCESS OF CONCENTRATION PHOSPHATIC ORES WHICH COMPRISESAGITATING AND AERATING AN AQUEOUS SUSPENSION OF SAID ORE IN ADMIXTUREWITH AT LEAST ONE SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF HUMINOBTAINED AS A PRECIPITATE IN THE ACID HYDROLYSIS OF AT LEAST ONE CRUDEPROTEIN, DISTILLATES OF SAID HUMIN, ORGANIC SOLVENT EXTRACTS OF SAIDHUMIN AND SOLVENT-FREE EXTRACTS THEREOF, AND AQUEOUS EXTRACTS OF SAIDHUMIN AND SOLVENTFREE EXTRACTS THEREOF.